Earlier in November, for the second consecutive year, scores of Partula nodosa snails were placed in the Papehue Valley in Tahiti, the St. Louis Post-Dispatch (http://bit.ly/2gMblSk ) reported.

And the zoo — thanks in considerable part to the duo's tireless work — can take major credit for being a main player in a program that is succeeding not only in saving that snail species, but also in returning it to its native French Polynesia.

Of the 870 Partulas put into the wild, 630 were from St. Louis — all lovingly fed, cleaned and otherwise cared for by Miller and Mills. Last year, the first year the snails went back to the wild, the zoo contributed 140 snails.

"We're the Snail Ladies," Miller said. "That's what they call us."

Bob Merz, the zoo's manager of invertebrates, said the women "may just have saved a species. It really shows how one person, or two people, can make a difference."

Glenn Frei, a keeper of invertebrates who works closely with Miller and Mills, also said he supported the title.

"They earned it," Frei said. "They're one of the big reasons the snails are still around."

So unassuming that no one has ever bothered to give it a nickname, the Partula is about the size of a jelly bean, a drab greenish-brown, striped jelly bean.

But let's slow down and go back to the 1980s, when a surge in escargot consumption inspired food growers to import bigger, meatier snails into French Polynesia. Those imported meaty mollusks, known as rosy wolf snails, are as big as an adult human's entire thumb.

While that may be perfect for an order of escargot, no one realized that before the rosy wolf snails ended up on the plates of gastronomes, they feasted on their new favorite food: Partula snails.

"By the late 1980s," Frei said, "they were virtually extinct in the wild."

Slugging forward to the early 1990s, British conservationists showed up at the door of Ron Goellner, the zoo's renowned keeper and conservationist who died in 2006.

They had a plan calling for several zoos in the U.S. and Europe, led by the London Zoo, to become caretakers for Partulas. In time, the species could possibly be returned to its native islands.

Goellner recruited Miller and Mills to work with the snails.

"The program is part of the zoo's mission to act as a lifeboat" for threatened and endangered species, said Merz, who cheerfully defined his supervisory responsibilities as "if it ain't got a spine, it's mine."

Mills said that the lifeboat aspect, "the feeling like your work has a purpose," was what had kept her engaged in the program for 23 years.

"It's important to show that we care about something so small; not just the big, popular ones," Mills said.

So Miller, from south St. Louis, and Mills, a Kirkwood resident, each comes once a week to care for the less cuddly. They do so in a white room lit with fluorescent tubes and jammed with terrariums, cages and shelves holding plastic containers filled with Partulas.

Right now, after the shipment to Tahiti, there are about 1,000 Partulas on site. As many as 3,500 have been there at one time, and the women estimate they've cared for more than 10,000 over the years.

"I remember when this all started, back in 1993," Miller said. "We didn't have this (insectarium, built in 2000), so we sat at desks in Ron's office and took care of the snails."

The care consists of several tasks: First, the snails need to be removed from their containers, which must be cleaned.

"If it smells like ammonia, you know you have a problem," said Mills, who said small bugs and bacteria can find their way into the containers and kill snails.

"And there have been times we open a container and it was all fuzzy," Mills said. "And that's not good either."

Then the women mix up snail food, a not-altogether-malodorous green paste made of instant oats, chalk, nettles, vitamins and trout food. They smear some paste on the sides of the container and put the snails back at the bottom. Hungry ones find their way up to the sides.

When it comes time to ship out snails that have been selected for placement in the wild, the women pack them to be shipped to other zoos for independent evaluation.

"We wrap them in a tissue, insert them into something like a cardboard toilet paper roll, pack the ends with tissues and then stack them in a shipping box," Miller said.

As docents, they also talk to youth groups and school classes, which have different outlooks than adults.

"You know, kids don't look at animals like snails or snakes and think they're gross. They're think they're cool," said Mills, a former high school teacher who grew up in Southern California and was "born at Hollywood Hospital."

"I was a horse girl when I was young. I used to volunteer to work at the stables they kept in Griffith Park in Los Angeles," she said. "The big perk of the job was that I got to ride a mule."

Miller is a St. Louis native who majored in biology at Fontbonne University and worked for years in a pharmaceutical laboratory. She currently has a toy poodle as a pet, and has lived with cats and dogs her whole life.

"Had a rabbit when I was a kid, one my sister saved from the lab at Maryville College when she found out they were going to sacrifice them after testing," Miller said.

"We were going to call it Peter, until we found out it was a girl," she said. "So it became Patrinka."

Both women said they had no plans to drop out of the program. In fact, the only thing they are tired of are futile attempts to make them tell snail jokes.

"Trust me," Miller said, more as a warning than a suggestion, "we've heard them all."